Hydromorphone

General Information

Hydromorphone, a derivative of morphine, is a centrally-acting analgesic with a high binding affinity for the mu-opioid receptor. Hydromorphone is also a more common synonym for dihydromorphione and dimorphone.1 Many narcotics users consider it the "gem" of the opiate world because of its potency and availability in solutions meant for injection. The most well-known brand name containing hydromorphone is Dilaudid®. For a short period of time, an extended-release oral formulation known as Palladone® SR was available in the United States; however, it was taken off the market in July 2005 after it was found that imbibing alcohol while on the medication could cause a deadly amount of the drug to be released into the body. Palladone® SR is reported still available in the United Kingdom.

Pharmacology & Pharmacokinetics

Peak plasma levels generally occur 30 to 60 minutes after administration of hydromorphone. Over 95% of the drug is metabolized in the liver, with only a very small amount remaining unchanged in excreted urine. The half-life of hydromorphone when administered via IV is about 2.3 hours. In a study using Dilaudid IR tablets, the half-life was as high as 40 hours in patients with renal (kidney) impairment. Because of this large deviation, patients with kidney problems should be started on lower doses. The analgesic effect of 5 mg of hydromorphone is equal to about 30 mg of oral morphine sulfate.2

Legal Status

In the United States, this drug is a Schedule II substance, making it illegal to use or possess without a prescription. Schedule II substances, such as dextroamphetamine, morphine, oxycodone, and cocaine, meet the following criteria according to the Controlled Substances Act:

The drug or other substance has a high potential for abuse.

The drug or other substance has a currently accepted medical use in treatment in the United States (or) a currently accepted medical use with severe restrictions.

Abuse of the drug may lead to severe psychological or physical dependence.

Side Effects

Dizziness

Nausea and vomiting

Constipation

Flushing

Sweating

Euphoria or dysphoria

Dry mouth

Sedation

Pruritus

Withdrawal

Hydromorphone is extremely addictive, and is often used as a last resort in pain management. Withdrawal symptoms generally begin within 24 hours after the last dose and increase in severity over the next 72 hours. Acute symptoms are mostly gone after 3-5 days, and the rest dissipate during days 5-14. Sometimes after quitting the user will develop a protracted withdrawal syndrome, which typically lasts two to six months, though there have been instances where it has lasted even longer. In addition, it can be difficult to draw the line between a protracted withdrawal syndrome and preexisting mental problems. The official name for this protracted withdrawal syndrome is post-acute withdrawal syndrome (PAWS). Listed below are general symptoms of opioid withdrawal: